BSA liposomes were prepared with approximately 100 nm mean particle size under rather gentle experiment conditions, and two-colorimetric coomassie brilliant blue protein was employed to measure the free drug in the entrapped efficiency (EE%) determination of BSA liposomes. Gel filtration was used to measure the EE%, and several Sephadex gels were examined by the separation of liposomes and free drug. To determine the free drug, three methods were compared on two-colorimetric UV spectrophotography, Bradford and two-colorimetric coomassie brilliant blue, separately. Two-colorimetric coomassie brilliant blue process increased the accuracy and improved the sensitivity of the assay about 20-fold comparing with the Bradford method. Two-colorimetric coomassie brilliant blue assay appeared to be more sensitive and showed broader dynamic range to measure the free BSA in the EE% determination of BSA liposome.
Colorimetry ; Drug Carriers ; Drug Compounding ; Electrophoresis, Gel, Two-Dimensional ; Liposomes ; Particle Size ; Rosaniline Dyes ; Serum Albumin, Bovine ; administration & dosage ; analysis ; Spectrophotometry, Ultraviolet

OBJECTIVETo study isolation, identification and differentiation characteristics of dermal multipotent stem cells from human of different age in vitro culture.

METHODSSkin samples( 1 cm x 1 cm) were harvested from fetus, infant, adult and elderly. The original clones were screened in stem cell medium. The diameter and number of clones were recorded. Analysis of each clone and determination of the expression of various related proteins were carried out.

RESULTSThe number of suspended clones from normal skins of fetus, infant, adult and the elderly were (20. 1 +/-2. 5) x 102 , (15. 8 +/-5. 7) x 102, (10. 8 +/-1.3) x 10(2), (6.2 +/- 1.4) x 10(2), respectively ( P <0.01), while the diameter of the clones from them were (83 +/-12) microm, (55 +/- 10) microm, (46 +/- 12) Lm, (42 +/-8) microm, respectively ( P <0.05). Cloned cells from fetus, infant, adult and elderly could differentiate into neuron cell , neuroglia cell, smooth muscle cell, and adipocyte. The clones from fetus were inclined to differentiate into neuron cells, but those from infant were inclined to differentiate into neuroglia cells, and those from adult and elderly were inclined to differentiate into adipocytes. After 1 month of culture, the clone forming rate of the cells from fetus, infant, adult and elderly were 41. 1% , 25.5% ,17.7% ,15.2% , respectively. The individual clone cells also showed ability of multidirectional differentiation. Nestin, fibronectin, c-Myc, STAT3 and hTERT protein were expressed in all clones.

CONCLUSIONMultipotent stem cells with multi-direction differentiation and proliferation can be efficiently isolated from dermis of human of different age in stem cell culture medium. The number, proliferation and differentiation of dermal multipotent stem cells can be affected by age.

Aborted Fetus ; cytology ; Adult ; Age Factors ; Aged ; Aged, 80 and over ; Cell Differentiation ; Cell Separation ; Cells, Cultured ; Child ; Child, Preschool ; Dermis ; cytology ; Female ; Humans ; Infant ; Male ; Middle Aged ; Multipotent Stem Cells ; cytology ; Pregnancy ; Pregnancy Trimester, Second